Contraction and center joint



Mardl R. R. ROBERTSON commoner: AND CENTERJOI'NT Filed Nov. 2, 193a Ross er A. Roam 76 ON Patented Mar. 12, 1940 warren stares ginger rarest 7 Claims.

The present invention relates to road joints and more particularly to contraction and center joints provided with anchoring means forming part of a transverse seal plate which separates upper and lower joint plates each of which is provided with staggered flanges contacting the seal plate. and rigidly secured thereto by means of lugs or fingers struck from the intermediate transverse seal plate. The improved joint is so constructed that the packing of concrete forming the road slabs on opposite sides of the joint is made more complete or perfect by providing the lower joint plate with a series of openings beneath the transverse seal plate thereby obviating air pockets being formed beneath the seal plate and allowing the concrete when poured to :ompletely fill the corners and spaces beneath the seal plate as well as above the same.

It is an object of this invention to provide a mediate transverse member acts as a loadtransmitting means between the road slabs and has rigidly clamped thereon upper and lower joint plates, with the lower joint plate having openings provided therein below the transverse member to insure the complete packing of concrete on opposite sides of the joint beneath the transverse member as well as above the same.

It is a further object of this invention to provide a contraction or center joint comprising intersecting joint plates one of which is provided with openings to insure the complete and solid packing of concrete below the other of the joint plates and insuring the formation of road slabs 35 Without the formation of air pockets or hollows at the intersecting corners of the joint plates.

It is also an object of this invention to provide a contraction or center joint wherein upper and lower joint plates are provided with staggered 40 flanges which are rigidly clamped to a transverse seal plate by means of fingers or lugs struck from the seal plate and tightly clamped against the staggered flanges to grip and deflect portions of said flanges into the openings resulting from 45 the formation of the gripping lugs or fingers.

It is an important object of this invention to provide an improved and simplified form of con traction or center joint adapted to be embedded in concrete to separate road slabs by means of vertical members While horizontal members are formed to tie the slabs together, said joint having portions thereof provided with openings permitting the escape of air during the pouring of concrete to form the road slab and insuring a complete packing of the concrete particularly contraction or center joint wherein an inter-- in the-corners of the joint below the transverse members, which corners ordinarily are not properly filled, causing the formation of defective road slabs.

Other and further objects of this invention will be apparent from the disclosures in the speciflcation and the accompanying drawing.

The invention (in a preferred form) is illustrated in the drawing and hereinafter more fully Figure is an enlarged fragmentary detail section taken on line V-V of Figure 2.

As shown on the drawing:

The contraction or center joint of this invention comprises a joint-forming mechanism which is adapted to be supported upon a road subgrade l and is then embedded in concrete which forms road slabs 2- and 3 on opposite sides of the jointforrning mechanism.

The improved joint which may be used either as a center joint or as a contraction joint, is constructed of sheet metal and comprises a main body portion consisting of an upper plate 6, the lower margin of which is cut to provide a plural-. ity'of sections which are deflected alternately in opposite directions at substantially right angles to the plate l to provide staggered flanges 5, as clearly illustrated in Figure 1. Also forming part of the main body portion of the joint is a bottom plate 6, the upper margin of which is cut at spaced intervals to provide a plurality of sections which are alternately deflected outwardly at substantially right angles to the plate 6 to form a plurality of staggered flanges l. The staggered flanges l, as clearly illustrated in Figures 2, 4 and 5, are arranged to be positioned beneath the spaces between the upper flanges 5.

Separating the flanges 5 and l of the upper and lower plates of the joint is a transverse seal plate 3 which forms the middle portion of the joint. The staggered flanges ii of the top plate of the joint seat against the top surface of the seal plate 8 while the staggered flanges l of the lower joint plate seat against the bottom surface of the seal plate 8 beneath the spaces between the flanges 5. This arrangement positions the flanges 5 and l diagonally with respect to one another on opposite sides of the seal plate 8.

For the purpose of rigidly securing the joint plates 4 and 6 to the transverse seal plate 8, said plate 8 has struck upwardly therefrom staggered groups of gripping lugs or fingers 9 leaving openings Iii in the plate 8. The staggered groups of upwardly projecting lugs 9 are clamped downwardly with considerable pressure and grip over the longitudinal marginal edges of the top flanges 5 causing the portions of said flanges beneath the lugs 9 to be slightly deflected downwardly into the openings ill, as illustrated in Figure l. Also struck downwardly from the transverse plate 8 are a plurality of staggered groups of lower gripping lugs or fingers H which are clamped over the marginal longitudinal edges of the lower flanges with considerable pressure to cause the portions of the flanges T engaged by the lugs H to be deflected upwardly into openings l2 resulting from the formation of the lugs H. The tight clamping of the lugs 9 and H over the flanges 5 and 1 respectively of the joint plates i and 6 rigidly secures the plates 4, B and 8 together to form the joint structure.

Also struck outwardly from the two longitudinal margins of the seal plate 8 are a plurality of anchor blades or tabs !3, the formation of which leaves rows'of openings H3 in the plate fl? on opposite sides of the joint plates i and t. The anchor blades l3 are adapted to be embedded in the concrete road slabs 2 and as illustrated in Figure 3, to tie the road slabs together through the seal plate 8.

For the piupose of insuring the complete packing of the concrete beneath the seal plate 8 on opposite sides of the upper portion of the lower joint plate 6 and to obviate the formation of any air pockets in the road slab-s beneath the joint plate 8, the lower joint plate 6 is provided with a row of spaced openings E5 in the upper portion of said plate 6 below the flanges l. The openings l5 during the pouring of the concrete for the formation of the road slabs permit the concrete to project through the openings l5, allowing the escape of air upwardly through the openings in the plate 8 thereby obviating the formation of air pockets beneath said plate 8 and permitting the concrete to completely fill the corners of the road joint beneath the plate l3 as well as above said plate.

It will of course be understood that various details of construction may be varied through a wide range without departing from the principles of this invention, and it is therefore not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. A road contraction or center joint for embedding between adjacent concrete road slabs, said joint comprising a seal plate embedded in the concrete to project from one road slab into an adjacent slab, anchoring blades struck from the seal plate and also embedded in the concrete road slabs, joint plates disposed on opposite sides of the seal plate, staggered flanges integrally formed on each of the joint plates contacting opposite surfaces of the seal plate, and clamping members struck from the seal plate leaving openings therein, said clamping members deflected over the joint plate flanges with a force sufficient to deflect portions of the flanges into the openings in the seal plate.

2. A road contraction and center joint comprising an intermediate seal plate, joint plates disposed on opposite sides of the seal plate, staggered flanges integrally formed on the margins of the joint plates adjacent the seal plate and seated against opposite surfaces of said seal plate, said flanges of the joint plates being arranged to be disposed opposite the spaces between the flanges of the joint plate on the opposite side of the seal plate, and means. integral with the seal plate for gripping and rigidly clamping the joint plate flanges on the seal plate.

3. A road contraction and center joint comprising an intermediate seal plate, joint plates disposed on opposite sides of the seal plate at substantially right angles thereto, staggered flanges integrally formed on the margins of the joint plates adjacent the seal plate and seated against opposite surfaces of said seal plate, said flanges of the joint plates being arranged to be disposed opposite the spaces between the flanges of the joint plate on the opposite side of the seal plate, means integral with the seal plate for gripping and rigidly clamping the joint plate flanges on the seal plate, and anchoring members struck from the seal plate and leaving openings therein.

4. A road contraction and center joint for embedding between concrete roadslabs, said joint comprising an intermediate plate embedded in the concrete on opposite sides of the joint, an upper joint plate and a lower joint plate disposed on opposite sides of the intermediate plate and at substantially right angles thereto, said lower joint plate having a series of spaced openings provided therein adjacent the intermediate plate, flanges integrally formed on the upper joint plate and on the lower joint plate with the flanges of the upper joint plate contacting one surface of the intermediate plate and disposed diagonally with respect to the flanges of the lower joint plate contacting the opposite surface of the'intermediate plate, and clamping members integral with the intermediate plate and engaging and compressing portions of the flanges into openings in the intermediate plate.

5. A road contraction and center joint for embedding between concrete road slabs, said joint comprising an intermediate plate embedded in the concrete on opposite sides of the joint, an upper joint plate and a lower joint plate disposed on opposite sides of the intermediate plate and at substantially right angles thereto, said lower joint plate having a series of spaced openings provided therein adjacent the intermediate plate, flanges integrally formed on the upper joint plate and on the lower joint plate with the flanges of the upper joint plate contacting one surface of the intermediate plate and disposed diagonally with respect to the flanges of the lower joint plate contacting the opposite surface of the intermediate plate, clamping members integral with the intermediate plate and engaging and compressing portions of the flanges into openings in the intermediate plate, and anchoring blades struck from the intermediate plate and embedded in the concrete road slabs on opposite sides of the joint.

6. A contraction and center joint for embedding between concrete road slabs, said joint comprising an intermediate plate, main joint plates disposed on opposite sides of the intermediate plate at substantially right angles thereto, flanges on the main joint plates contacting opposite surfaces of the intermediate plate, clamping means on the intermediate plate engaging the flanges of the main joint plates for rigidly holding the main joint plates secured to the intermediate plate, the lower one of said main joint plates having a series of spaced openings therein adjacent the intermediate plate allowing the escape of air when the concrete is poured to form the road slabs and allowing the solid packing of the conic crete beneath the intermediate plate in the corners of the joint and. obviating the formation of air pockets in the concrete road slabs.

7. A road. contraction and center joint for embedding between concrete roadslabs, said joint comprising an apertured seal plate, joint plates on opposite-sides of the seal plate, and securing means deflecting portions of the joint plates into the apertures in the seal plate to hold the plates secured together.

ROBERT R. ROBERTSON. 

